Rotating publicity device with prism combination - produces continuous wide angle of view with triangular prisms giving 120 degree spread

摘要

The mobile support gives continuous wide angle viewing of publicity texts. It is made up of a number of triangular prisms (5) placed in a circle between two flat rotating plates (3). The number of prisms gives use of the prism side face and also produces a cylinder of revolution. Each prism carries part of the image or text and makes an angle of 120 degrees with each turn. At each prism end is a pivot (6) fitting in a slot (7) of a shoe sliding freely in a radial slideway from head to foot of the plate fixture.